Exception Handling in Kotlin - Try, Catch, and Finally


Exception handling is an essential part of any programming language, and Kotlin provides robust mechanisms for handling exceptions gracefully. In this guide, we'll explore how to use try-catch blocks for exception handling and the role of the "finally" block.


Basic Exception Handling

Kotlin uses try-catch blocks to handle exceptions. Here's a basic example:

try {
    val result = 10 / 0
} catch (e: ArithmeticException) {
    println("An arithmetic exception occurred: ${e.message}")
}

In this example, a division by zero operation is attempted, and when an `ArithmeticException` is thrown, it's caught in the catch block.


Catching Multiple Exceptions

You can catch multiple exceptions using separate catch blocks:

try {
    val result = 10 / 0
} catch (e: ArithmeticException) {
    println("An arithmetic exception occurred: ${e.message}")
} catch (e: Exception) {
    println("An exception occurred: ${e.message}")
}

The "finally" block is used for code that should be executed regardless of whether an exception was thrown or not. It's often used for cleanup tasks:

try {
    // Perform some operations that may throw exceptions
} catch (e: Exception) {
    println("An exception occurred: ${e.message}")
} finally {
    // Cleanup code, e.g., close resources
}

Custom Exceptions

You can create custom exceptions by extending the `Exception` class or its subclasses:

class CustomException(message: String) : Exception(message)
try {
    // Perform some operations
    if (somethingWentWrong) {
        throw CustomException("Something went wrong.")
    }
} catch (e: CustomException) {
    println("Custom exception: ${e.message}")
}

Conclusion

Exception handling in Kotlin using try-catch blocks is crucial for writing robust and reliable code. It allows you to gracefully handle unexpected situations and ensure your application continues to run smoothly. The "finally" block is useful for cleanup tasks, and custom exceptions help you handle application-specific error scenarios.


Happy coding!